Taxonomy term

september 2016

When paleontologists unearth a fossil and rock still entombs part of it, they take it to someone like fossil preparator Bob Masek, who cleans and prepares the fossil for scientific study, and sometimes for display in a museum. In the 1990s, Masek helped prepare “Sue,” the most complete Tyrannosaurus rex fossil ever discovered, which now stands in Chicago’s Field Museum of NaturalHistory.

In addition to their aesthetic and photogenic appeal, clouds play a crucial role in Earth’s climate and ecosystems, helping regulate temperatures by reflecting sunlight. All clouds — from fluffy cumulus to wispy cirrus — grow from seeds that, more often than not, are tiny particles of pollen, dust or chemical aerosols that float into the atmosphere from Earth’s surface. Sulfuric acid, a byproduct of volcanic eruptions and fossil fuel combustion, is one of the most ubiquitous precursors to atmospheric aerosols today and has long been thought to play a major role in modern cloud formation. But what about earlier in Earth’s history, before humans impacted the atmosphere as much? Three new studies, representing both experimental and field data, suggest that the planet’s plants and trees might have done just fine on their own pumping cloud-forming aerosols into the skies.

The mountains of eastern North America, like the Appalachians, Adirondacks and White Mountains, are old: They grew as the pieces of the supercontinent Pangea collided and assembled more than 300 million years ago. It’s been long thought that, after forming — and subsequently undergoing additional uplift and deformation due to rifting during the opening of the Atlantic Ocean — the mountains fell dormant between about 160 million and 200 million years ago. But new work is adding to a growing body of evidence suggesting the ranges were tectonically active well after that.

Guatemala is home to 22 volcanoes, several of which visitors can climb. The most popular is the active Volcán Pacaya; the hike is relatively easy, the views spectacular, and visitors can roast marshmallows near the summit.

Most people think of landslides as fast-moving events, but many slides creep slowly, advancing over hundreds or thousands of years. In a new study, researchers looking at creeping landslides in California have revealed an unexpected consequence of the state’s ongoing drought: Many of the slides have nearly stopped due to the lack of water in the soil.

In 1241, the armies of the Mongol Empire, continuing their campaign through Asia and Europe, invaded western Hungary. Before long, however, the Mongols withdrew their forces, beating a sudden retreat that has long baffled historians. Now, drawing on high-resolution climate data from tree rings, researchers may have found a clue as to why: It seems wet weather created adverse conditions for the Mongol army, eventually forcing it to retreat from what was to become historically its westernmost advance.

The Triceratops family tree just got a little spikier. A decade ago, a retired nuclear physicist uncovered the large skull, legs, hips and backbone of a dinosaur on his land near Winifred, Mont. Now, the remains have been identified in a new study as a new member of the ceratopsid family, dubbed Spiclypeus shipporum, meaning “spiked shield.”

Today, Alfred Wegener’s name appears in almost every geology textbook. He is celebrated as the father of the continental drift hypothesis, the forerunner of plate tectonics. This recognition is rather recent — since about the early 1970s, when plate tectonics became a unifying theory to explain the origins of continents, oceans, mountains, volcanism and many other geologic processes. During his life, Wegener’s hypothesis was rejected by many geologists, more so in North America than in Europe. The dramatic change of his status from heretic to hero thus makes Wegener’s story even more fascinating, not only to earth scientists but to general readers as well.

New fossils found in southern China hint that the earliest herbivorous marine reptiles got off to a bizarre start: Atopodentatus unicus, which lived about 244 million years ago and sported a unique hammerhead-like snout for grazing underwater plants, sheds light on how the earliest marine reptiles began experimenting with herbivory after the Permian mass extinction, which killed off 96 percent of marine organisms about 252 million years ago. This “Great Dying” event left vast holes in the ecology of the Early Triassic, and a diversity of new feeding styles evolved to occupy the open niches.